Hydraulic pressure generating apparatus for use in an emergency

ABSTRACT

A hydraulic pressure generating apparatus for use in an emergency, comprising: a body of a substantially cylindrical shape; a first end plug secured in a fluid tight fashion in the hollow portion of said body at its one end in a manner to close said hollow portion, having an end portion, which is coupled with an external fluid piping, on its outer surface and having a through-hole extending along the center line thereof; a second end plug secured in a fluid tight fashion in said hollow portion of said body at the other end thereof in a manner to close said hollow portion, said hollow portion containing therein flammable material consisting of instantaneously self-combustible material and including an igniting means positioned therein but adjacent to said self-combustible material; and a free piston fitted in said hollow portion slidably and in a fluid tight fashion between both said end plugs to thereby define a gas chamber and a fluid chamber on opposite sides of said piston.

United States Patent 11 1 Haraikawa [451 Aug. 29, 1975 Tetsuo I-Iaraikawa, Funabashi, Japan [75] Inventor:

[73] Assignee: Tokico Ltd., Kawasaki, Japan [22] Filed: Oct. 15, 1973 21] Appl. No.: 406,613

Primary Examiner-Martin P. Schwadron Assistant Examiner-H. Burks, Sr. Attorney, Agent, or Firm-Wenderoth, Lind & Ponack 5 7 ABSTRACT A hydraulic pressure generating apparatus for use in an emergency, comprising: a body of a substantially cylindrical shape; a first end plug secured in a fluid tight fashion in the hollow portion of said body at its one end in a manner to close said hollow portion, having an end portion, which is coupled with an external fluid piping, on its outer surface and having a throughhole extending along the center line thereof; a second end plug secured in a fluid tight fashion in said hollow portion of said body at the other end thereof in a manner to close said hollow portion, said hollow portion containing therein flammable material consisting of instantaneously self-combustible material and including an igniting means positioned therein but adjacent to said self-combustible material; and a free piston fitted in said hollow portion slidably and in a fluid tight fashion between both said end plugs to thereby define a gas chamber and a fluid chamber on opposite sides of said piston.

4 Claims, 4 Drawing Figures PATENTEU Auszsms sum 1 OF 2 HYDRAULIC PRESSURE GENERATING APPARATUS FOR USE IN AN EMERGENCY This invention relates to a hydraulic pressure generating apparatus for use in an emergency, and more particularly to an apparatus adapted to supply a high pressure fluid to a desired device which requires said fluid in the event of an emergency.

Hitherto, there has been known a system which is intended to supply a high pressure fluid to an associated piece of equipment, by releasing the high pressure fluid stored in an accumulator or the like by using an emergency signal. However, such has suffered from disadvantages in that there tends to occur a decrease in the internal pressure in the accumulator due to the leakage of fluid during storage or duringthe inoperative condition for a long period of time or in that there arises the need to make the size of the apparatus larger, because of the provision of an accumulator.

On the other hand, with an energy storing system using means such as a mechanical spring, it becomes necessary to use a large size spring to generate a high level of force required. In addition, there is a danger of an associated piece equipment of being operated or actuated due to the inadvertent release of the stored energy, in the event of the failure of such a mechanism.

This invention is directed to avoiding such drawbacks by using a hydraulic pressure generating apparatus adapted for use in an emergency which utilizes a combustion-gas pressure converting system.

It is accordingly an object of the present invention to provide a hydraulic pressure generating apparatus for use in an emergency which will insure the maintenance of a high level of reliability for a long period of time.

It is a further object of the invention to provide a hydraulic pressure generating apparatus of the type described which insures positive operation and which requires a short period of time until the generation of the high pressure is achieved.

It is a further object of the invention to provide a hydraulic pressure generating apparatus of the type described which is simple in construction and easy to manufacture.

It is a still further object of the invention to provide a hydraulic pressure generating apparatus of the type described which permits ready re-use after the operation thereof.

It is a yet further object of the invention to provide a hydraulic pressure generating apparatus of the type described which can be attached in a simple manner to the end of a piece of equipment which requires a high pressure fluid, said apparatus being replaceable with another, i.e., in a manner similar to replacing a tape cassette in a tape-recorder.

It is a further object of the invention to provide a hydraulic pressure generating apparatus of the type described which permits ready maintenance.

According to the present invention, there is provided a hydraulic pressure generating apparatus for use in an emergency, comprising: a body of a substantially cylindrical shape; a first end plug secured in a fluid tight fashion in the hollow portion of said body at its one end in a manner to close said hollow portion, having an end portion which is coupled with an external fluid piping and having a through-hole extending along the center line thereof; a second end plug secured in a fluid tight fashion in said hollow portion of said body at the other end thereof in a manner to close said hollow portion thereat, said hollow portion containing therein flammable material consisting of instantaneously selfcombustible material and including igniting means positioned therein but adjacent to said self-combustible material; and a free piston fitted in said body slidably in a fluid tight fashion between both said end plugs to I thereby define a gas chamber and a fluid chamber on opposite sides of said piston.

Included in the flammable materials consisting of an instantaneously self-combustible materials which are employable in the present invention are, for instance, explosives and the like. This saves the space, in-which such a material is housed, presents a simple mechanism for gasifying said material and isconvenient for maintaining the quality of the flammable materialas well as the safety thereof. This further leads to ready manufacture and handling, with a high level of reliability, in case it is stored for a long period of time.

A further advantage is that, since the gas pressure is transmitted through a free piston to the fluid in a desired position, a high level of fluid pressure may be generated for an extremely short time.

The hydraulic pressure generating apparatus according to the present invention is useful for operating a number of devices such as an emergency braking device for use in an automobile, an emergency stopping device for use such as in a hydraulic press mechanism, an emergency valve-closing device for use in the events of tire, earthquake, etc., which device is used in an oil feeding system for fuel oil or the like, a release device for use in an emergency door, an emergency decoupling device for use such in the event of fire on a railroad vehicle.

The above mentioned and other objects and features of the present invention will become apparent from the following detailed description taken in conjunction with the drawings which show embodiments of the invention, in which:

' FIG. 1 is a longitudinal cross-sectional view of the first embodiment of the present invention;

FIG. 2 is a longitudinal cross-sectional view of the second embodiment of the invention, coupled with a schematic diagram illustrating the principle of high pressure operated devices associated therewith;

FIG. 3 shows one embodiment of a free piston for use in the present invention, the construction thereof being different from that shown in FIG. 2', and

FIG. 4 shows another embodiment of a free piston for use in the present invention.

Referring now to FIG. 1, shown at l is a body of a substantially cylindrical shape, constituting the main body of a hydraulic pressure generating apparatus of the invention, the wall of said body defining a cylindrical hollow portion 2.

Shown at 3 is a first end plug adapted to close the hollow portion 2 at one end of the body 1, being secured in said body in a fluid tight fashion with a seal ring 4. Provided on the outer end of the end plug 3 is an end portion 3 which is to be coupled with high pressure fluid operated means (or a pipe connected to said means). As shown, the plug 3 is threadingly mounted in said body at a threaded portion 3" and is detachable as required. The external coupling portion 3' of the plug 3 has a threaded outer circumferential surface as shown at 3". Designated at 6 is a through-hole extending co-axially of the plug 3. Provided in the outer portion of the through-hole 6 is a closure member 7 in the form of a thin film or thin sheet. In the embodiment shown, the closure member 7 is seated on a shoulder portion 6' provided in the inner wall of said plug defining the hollow portion, with the outer periphery thereof being firmly fixed with a retaining nut 8 in a fluid tight fashion. The closure member 7 is so designed as to be susceptible to breakage, when subjected to a pressure exceeding the predetermined value or such that it may be broken when connected with a piece of equipment 5. Alternatively, the closure member may be a detachable cap which is adapted to be detached therefrom at the time of connection. Represented by 9 is a seal ring provided for the connection of the plug 3 with the equipment 5. Shown at 10 is a second end plug secured in the body 1 at the other end thereof, thereby closing the hollow portion therein in a fluid tight fashion. The end plug 10 has a hollow portion 10', in which is charged a flammable material 11 consisting of instantaneously self-combustible material such as explosives, and has therein an igniting means 12 adjacent to said combustible material charged, such as for instance, an electric heater or a spark plug. In the embodiment shown, the plug 10 is secured in the body 1 threadingly in fluid tight fashion at the threaded portion 10". The plug 10 is detachable from the body 1, as required.

Shown at 14 is an emergency signal transmitting means to feed an electric signal to the igniting means 12, in the event of an emergency, to actuate said igniting means 12.

Designated at 15 is a free piston fitted in the hollow portion 2, slidably and in a fluid tight fashion, intermediate said end plate 3 and end plate 10, thereby defining a gas chamber 16 and a fluid chamber 17 on the opposite sides thereof. The fluid chamber is designed to be filled with hydraulic fluid. Shown at 18 is a seal ring fitted on the outer circumferential surface of the piston 15.

In operation, in the event that an emergency condition takes place, the emergency signal transmitting means 14 is operated manually or automatically to actuate the igniting means 12 to thereby ignite the flammable material 11.

In this manner, the flammable material such as explosives catches fire instantaneously, to thereby produce a great amount of gas in the gas chamber 16, such that the pressure within the gas chamber 16 will be increased instantaneously.

As a result, the piston 15 receives a high pressure on its one side to thereby move to the left as viewed in the drawing, exerting the pressure on the fluid contained in the fluid chamber 17 for delivering the same to the high pressure operating equipment 5. Thus, the high pressure operating equipment 5 will be operated instantaneously under the aforesaid high pressure.

The apparatus described is simple in construction and hence easy to manufacture, and compact in size. Because of the provision of the coupling end portion of the first end plug, the whole body of the apparatus may be replaced with another after each operation very easily in a manner similar to replacing a tape cassette in a tape-recorder. In addition, the provision of the closure member for use in preventing leakage of the fluid from the fluid chamber renders easier the handling of the apparatus as an independent unit.

In addition, the attachment of the respective plug to the body by means of threaded construction facilitates disassembly, cleaning and re-assenibly and hence enables re-use thereof.

A still further advantage is that an accident may be prevented, because the gas under the high pressure may be enclosed within the body, with the piston abutting against the inward surface of the attaching plug, even if there arises leakage of the fluid due to any trouble incurred to the piping downstream of said attaching plug.

FIG. 2 illustrates the second embodiment of the invention, in which similar parts are designated by the similar reference numerals.

In FIG. 2, shown at 20 is a transfer pipe for flammable fluid such as gasoline, at 21 an emergency shut-off valve provided in said pipe 20 and at 22 an operating handle for the valve 21.

Designated at 5 is an operating cylinder communicating through the pipe 19 with the hydraulic pressure generating device, and at 24 a piston slidably fitted in the cylinder body. The piston rod 25 of the piston 24 is linked to the operating handle 22 of the valve 21. Shown at 23 is a fluid chamber of the operating cylinder. The fluid is filled between the fluid chamber 17 of the emergency hydraulic pressure generating apparatus and the fluid chamber 23 of the operating cylinder 5.

A description will now be given of the operation of this embodiment.

In the event of fluid leakage due to the failure of the pipe 20, such trouble is detected and then the hydraulic pressure generating apparatus will be operated manually or automatically upon detecting such an emergency condition. As in the previous embodiment, the fluid under the high pressure will be fed to the cylinder 5 for an extremely short time, thereby closing the valve 21.

Meanwhile, no problem will arise, as long as the piston 15 can operate smoothly in a manner as has been described. However, in case there is developed rust or corrosion on the inner surface of the cylinder due to a long storage time, i.e., in case there arises a so-called rust-seizure, or in case the cylinder body 1 of the hydraulic pressure generating apparatus is subjected to deformation due to an inadvertent external force, then the internal pressure will be increased instantaneously, thereby exceeding the limit pressure specified for the body 1 or associated parts thereof. As shown in FIG. 2, according to another aspect of the invention, the wall of the bottom portion 15' of the piston 15 can be thinner than the other portions of the piston. As a result, in the event of the piston 15 being subjected to the rust seizure or in the event that the piston stops midway in the required stroke, the internal pressure will undergo an unusually rapid increase, such that the bottom portion 15 will be broken at least at a predetermined pressure, and thus the high pressure gas can be bled through the piston 15 outside.

This apparently results in the mixture of the gas with the liquid, although the pressure within the hydraulic pipe may be maintained at a desired high value, whereby the operating cylinder 5 will be operated to actuate the valve 21, thus closing the pipe 20. In other words, the prevention of the breakage of the hydraulic pressure generating apparatus as well as the safety of the pipe 20 itself may be achieved.

The piston as shown in FIGS. 3a and b is a modification of the piston shown in FIG. 2, with the bottom portion being provided beforehand with grooves in shapes such as a cross, asterisk or Y to thereby reduce the strength of the bottom portion, such that the bottom portion may be readily broken, when subjected to abnormally high pressure. The provision of grooves may also apply to the bottom portion of a small wall thickness.

FIG. 3b is a longitudinal cross-sectional view showing the condition in which the bottom portion of the piston 15 of FIG. 3a has been broken inwardly clue to the generation of the high pressure gas.

The piston the longitudinal cross-sectional view of which is shown in FIG. 3 includes a bottom portion consisting of a safety sheet 1512 made of a fragile material or of such a shape or dimensions which are susceptible to the breakage, said sheet 15b being fitted in a cylindrical body 150 of the piston 15. In the embodiment as shown, a separate piece of a sheet is seated, with a ring nut 15c pressing said sheet against the internal shoulder portion of the cylindrical body 8a, thereby closing the through-hole extending through the cylindrical body 15a.

As in the previous two embodiments, the piston in this embodiment is also designed to be broken at the safety sheet 15b, when subjected to abnormally high pressure. The piston having a construction described thus far may be made of a pipe by working the same, not to mention, by casting, thus presenting considerable advantages for manufacture.

What is claimed is:

l. A hydraulic pressure generating apparatus for use in an emergency comprising:

a hollow cylindrical body;

a first plug secured to one end of the body and closing said one end;

an end fitting extending outwardly from the first plug for releasably coupling the end fitting with an external piping;

a cup shaped second plug sealingly and detachably connected to the other end of said body and closing said other end of said body;

a self-combustible material disposed in the second ignition means in said second plug for firing the selfcombustible material from outside of the cylinder:

a piston freely slidably and sealing fitted in the body between said plugs for defining a fluid chamber between the piston and the first plug and a gas chamber between the piston and the second plug and normally disposed adjacent to the second plug and being unconnected therewith, a portion of the piston having strength less than the remaining portion thereof, the strength being sufficient for preventing the breakage of the body until abnormally high pressure is created in the gas chamber, whereby when said self-combustible material is fired said free piston is moved toward the first plug by gas pressure created by expansion of the selfcombustible material and fluid contained in the fluid chamber is compressed and flows into the external piping.

2. A hydraulic pressure generating apparatus as set forth in claim 1, wherein the center portion of said free piston has a smaller wall thickness than the other por tion thereof.

3. A hydraulic pressure generating apparatus as set forth in claim 1, wherein the bottom portion of said free piston is provided with a groove or grooves having a shape such as a cross or the like.

4. A hydraulic pressure generating apparatus as set forth in claim 1, wherein at least part of the bottom portion of said free piston consists of a safety sheet made of a fragile material or of a shape susceptible to breakage, said sheet being incorporated in said piston in a fluid tight fashion. 

1. A hydraulic pressure generating apparatus for use in an emergency comprising: a hollow cylindrical body; a first plug secured to one end of the body and closing said one end; an end fitting extending outwardly from the first plug for releasably coupling the end fitting with an external piping; a cup shaped second plug sealingly and detachably connected to the other end of said body and closing said other end of said body; a self-combustible material disposed in the second plug; ignition means in said second plug for firing the selfcombustible material from outside of the cylinder: a piston freely slidably and sealing fitted in the body between said plugs for defining a fluid chamber between the piston and the first plug and a gas chamber between the piston and the second plug and normally disposed adjacent to the second plug and being unconnected therewith, a portion of the piston having strength less than the remaining portion thereof, the strength being sufficient for preventing the breakage of the body until abnormally high pressure is created in the gas chamber, whereby when said self-combustible material is fired said free piston is moved toward the first plug by gas pressure created by expansion of the self-combustible material and fluid contained in the fluid chamber is compressed and flows into the external piping.
 2. A hydraulic pressure generating apparatus as set forth in claim 1, wherein the center portion of said free piston has a smaller wall thickness than the other portion thereof.
 3. A hydraulic pressure generating apparatus as set forth in claim 1, wherein the bottom portion of said free piston is provided with a groove or grooves having a shape such as a cross or the like.
 4. A hydraulic pressure generating apparatus as set forth in claim 1, wherein at least part of the bottom portion of said free piston consists of a safety sheet made of a fragile material or of a shape susceptible to breakage, said sheet being incorporated in said piston in a fluid tight fashion. 